[MTD] [NAND] Bug on atmel_nand HW ECC : OOB info not correctly written
authorRichard Genoud <richard.genoud@gmail.com>
Sun, 12 Oct 2008 06:42:28 +0000 (08:42 +0200)
committerDavid Woodhouse <David.Woodhouse@intel.com>
Tue, 14 Oct 2008 10:07:57 +0000 (11:07 +0100)
The functions that write the OOB info (on hardware ECC only) use the
HW_SYNDROME method.

This is not correct : the start position is "pos = eccsize + chunk" and
should be eccsize. So, the standard (nand_write_oob_std) function should
be used. This patch corrects this by using NAND_ECC_HW instead of
NAND_ECC_HW_SYNDROME.

This has only been tested on small pages nand flash.
(if anyone can test it on large pages that would be great).

kernel version : 2.6.27-rc2 (current git mtd-2.6)

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
drivers/mtd/nand/atmel_nand.c

index 3387e0d5076b06bad1af8506d73f673db99a1d2a..c98c1570a40b1ef5f3f3931ab4e0512be0341406 100644 (file)
@@ -173,48 +173,6 @@ static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len)
        __raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2);
 }
 
-/*
- * write oob for small pages
- */
-static int atmel_nand_write_oob_512(struct mtd_info *mtd,
-               struct nand_chip *chip, int page)
-{
-       int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
-       int eccsize = chip->ecc.size, length = mtd->oobsize;
-       int len, pos, status = 0;
-       const uint8_t *bufpoi = chip->oob_poi;
-
-       pos = eccsize + chunk;
-
-       chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
-       len = min_t(int, length, chunk);
-       chip->write_buf(mtd, bufpoi, len);
-       bufpoi += len;
-       length -= len;
-       if (length > 0)
-               chip->write_buf(mtd, bufpoi, length);
-
-       chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
-       status = chip->waitfunc(mtd, chip);
-
-       return status & NAND_STATUS_FAIL ? -EIO : 0;
-
-}
-
-/*
- * read oob for small pages
- */
-static int atmel_nand_read_oob_512(struct mtd_info *mtd,
-               struct nand_chip *chip, int page, int sndcmd)
-{
-       if (sndcmd) {
-               chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
-               sndcmd = 0;
-       }
-       chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
-       return sndcmd;
-}
-
 /*
  * Calculate HW ECC
  *
@@ -235,14 +193,14 @@ static int atmel_nand_calculate(struct mtd_info *mtd,
        /* get the first 2 ECC bytes */
        ecc_value = ecc_readl(host->ecc, PR);
 
-       ecc_code[eccpos[0]] = ecc_value & 0xFF;
-       ecc_code[eccpos[1]] = (ecc_value >> 8) & 0xFF;
+       ecc_code[0] = ecc_value & 0xFF;
+       ecc_code[1] = (ecc_value >> 8) & 0xFF;
 
        /* get the last 2 ECC bytes */
        ecc_value = ecc_readl(host->ecc, NPR) & ATMEL_ECC_NPARITY;
 
-       ecc_code[eccpos[2]] = ecc_value & 0xFF;
-       ecc_code[eccpos[3]] = (ecc_value >> 8) & 0xFF;
+       ecc_code[2] = ecc_value & 0xFF;
+       ecc_code[3] = (ecc_value >> 8) & 0xFF;
 
        return 0;
 }
@@ -476,14 +434,12 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
                        res = -EIO;
                        goto err_ecc_ioremap;
                }
-               nand_chip->ecc.mode = NAND_ECC_HW_SYNDROME;
+               nand_chip->ecc.mode = NAND_ECC_HW;
                nand_chip->ecc.calculate = atmel_nand_calculate;
                nand_chip->ecc.correct = atmel_nand_correct;
                nand_chip->ecc.hwctl = atmel_nand_hwctl;
                nand_chip->ecc.read_page = atmel_nand_read_page;
                nand_chip->ecc.bytes = 4;
-               nand_chip->ecc.prepad = 0;
-               nand_chip->ecc.postpad = 0;
        }
 
        nand_chip->chip_delay = 20;             /* 20us command delay time */
@@ -514,7 +470,7 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
                goto err_scan_ident;
        }
 
-       if (nand_chip->ecc.mode == NAND_ECC_HW_SYNDROME) {
+       if (nand_chip->ecc.mode == NAND_ECC_HW) {
                /* ECC is calculated for the whole page (1 step) */
                nand_chip->ecc.size = mtd->writesize;
 
@@ -522,8 +478,6 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
                switch (mtd->writesize) {
                case 512:
                        nand_chip->ecc.layout = &atmel_oobinfo_small;
-                       nand_chip->ecc.read_oob = atmel_nand_read_oob_512;
-                       nand_chip->ecc.write_oob = atmel_nand_write_oob_512;
                        ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_528);
                        break;
                case 1024: